[CR]Re: Backwards BB

(Example: Framebuilding:Technology)

From: "Stephen Barner" <Steve@sburl.com>
To: <classicrendezvous@bikelist.org>
References: <CATFOOD7sI59e8GWVh900003302@catfood.nt.phred.org>
Date: Sat, 13 Jul 2002 20:48:01 -0400
Subject: [CR]Re: Backwards BB

I have always thought the chainrings appear to have a different finish than the arms. I think they look so much different in that photo because of the angle at which they were photographed. Are Campy chainrings even anodized? Anyone ever try to polish one up? The outer on this bike looks like a NR with the inner web cut out.

The problem with putting a Campy Italian BB in backwards is that the rifling grooves in the cups will tend to suck contaminents in rather than pushing them out, as designed. I saw a guy accomplish the same thing by swapping Campy pedal axles to keep from rethreading the cranks on a homegrown tandem crossover setup. The first rain, and three pedals were all gritty inside.

Steve Barner, Bolton, Vermont, where my tandem has sadly hung upside down from the basement rafters since 1983.


----- Original Message -----


What's up with those Campy chain rings? I don't remember seeing anything like them in Cat-17. But, I've seen inner rings like that from SR. The outer ring looks like a cut-up later model (see safety stud). Those with a sharp eye may notice the finish on the arm/spider seems to be in marked contrast from the ring -- they match on my old bikes.

With Italian BB threads, who cares if the cups are reversed -- it works? But, it isn't the mark an experienced tech. What concerns me is that the BB axle seems to be in backwards!!! Look how closely the spider is to the cup and the big gap at the left arm!! I've been away from bikes for some time, is this some new method of improving the chain line?